2021 BMW 228i — Gran Coupe M Sport Brakes
The 2021 BMW 228i Gran Coupe M Sport Brakes shipped with 2 different factory tire sizes, depending on the wheel package it left the factory with (this can also reflect a staggered front/rear setup). Check your tire sidewall or door placard to confirm which one applies to your vehicle.
This trim shipped with more than one tire size (staggered fitment, front/rear, or optional wheel package). Confirm which one matches your vehicle by checking your tire sidewall or door placard.
225/40R18
| Section width | 225 mm |
|---|---|
| Aspect ratio (sidewall height) | 40% (90 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~25.1" |
| Revolutions per mile | ~804 |
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235/35R19
| Section width | 235 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (82.3 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~25.5" |
| Revolutions per mile | ~792 |
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What this size means for your BMW 228i
On the 2021 BMW 228i Gran Coupe M Sport Brakes, the factory 225/40R18 measures about 25.1″ in overall diameter with a 90 mm (3.5″) sidewall, and completes roughly 804 revolutions per mile. Its 40-series aspect ratio gives a low-profile sidewall tuned for sharper handling, common on sport trims and larger-wheel packages. In tire terms it is a passenger (P-metric / Euro-metric) size.
The 225/40R18 and 235/35R19 differ in both width and overall diameter (0.4″, 1.6%), which usually means a staggered front/rear setup — the two sizes are not interchangeable side to side, so match each to its correct axle.
Other 2021 BMW 228i trims
- xDrive Gran Coupe 225/45R17 / 225/40R18 / 235/35R19
BMW 228i tire sizes by year
- 2024 BMW 228i 225/45R17 / 225/40R18 / 235/35R19
- 2023 BMW 228i 225/45R17 / 225/40R18 / 235/35R19
- 2022 BMW 228i 225/45R17 / 225/40R18 / 235/35R19
- 2020 BMW 228i 225/40R18 / 235/35R19
- 2016 BMW 228i 205/50R17 / 225/40R18
- 2015 BMW 228i 205/50R17 / 225/40R18
- 2014 BMW 228i 205/50R17 / 225/40R18
How to read a tire size
A tire size like 225/45R17 breaks down into three parts:
the first number is the section width in millimeters
(the tire's width from sidewall to sidewall), the second is the
aspect ratio — the sidewall's height as a percentage of
that width — and the number after the "R" is the rim
diameter in inches. A letter prefix (P or LT) indicates
Passenger or Light Truck construction; its absence usually means
Euro-metric sizing.
Some trucks and off-road tires instead use "flotation" sizing, like
37X12.50R17 — here the numbers are the tire's overall
diameter and width in inches directly, with the rim diameter last.
Always verify against the tire information placard on your driver's-side door jamb or your owner's manual before purchasing — tire size can vary by factory option package even within the same trim.